In the following text the term “black water” refers to water that has been contaminated with any kind of filth, including residue, refuse, feces, and so forth, including gray water. The term “gray water” includes water which exits from water supplying systems or drinking water systems and is only slightly contaminated, for example, used wash water such as hand wash water. The term “wastewater” includes both gray water and/or black water.
Fuels with long chemical bonding chains based on hydrocarbons such as diesel fuel, kerosene, petroleum, and gasoline can be used in high temperature fuel cells because internal reformer processes take place in these fuel cell types. These internal reformer processes make these conventional fuels suitable for use in the energy production process in the fuel cell. For increasing the efficiency, such fuels should be pretreated before being supplied to the fuel cell or cells. For particular applications or types of use it is desirable to subject these fuels to an additional processing with water.
On board of aircraft and other mobile conveyances or in remote stationary facilities, water becomes available in the form of wastewater resulting from the use of the water supply by people. Fuel cells can be used, not only in their function for producing energy, but also for generating fresh water. For this purpose it is necessary to gain or recover sufficient quantities of free hydrogen molecules for the process that proceeds in the fuel cell. These hydrogen molecules can be supplied by fuels based on hydrocarbons. However, water may also be a source for providing hydrogen molecules. We have found that in a special case even wastewater can be used as a hydrogen molecule source.